Abstract
The papain-like protease PLpro is an essential coronavirus enzyme that is required for processing viral polyproteins to generate a functional replicase complex and enable viral spread 1,2 . PLpro is also implicated in cleaving proteinaceous post-translational modifications on host proteins as an evasion mechanism against host antiviral immune responses 3-5 . Here we perform biochemical, structural and functional characterization of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PLpro (SCoV2-PLpro) and outline differences with SARS-CoV PLpro (SCoV-PLpro) in regulation of host interferon and NF-κB pathways. SCoV2-PLpro and SCoV-PLpro share 83% sequence identity but exhibit different host substrate preferences; SCoV2-PLpro preferentially cleaves the ubiquitin-like interferon-stimulated gene 15 protein (ISG15), whereas SCoV-PLpro predominantly targets ubiquitin chains. The crystal structure of SCoV2-PLpro in complex with ISG15 reveals distinctive interactions with the amino-terminal ubiquitin-like domain of ISG15, highlighting the high affinity and specificity of these interactions. Furthermore, upon infection, SCoV2-PLpro contributes to the cleavage of ISG15 from interferon responsive factor 3 (IRF3) and attenuates type I interferon responses. Notably, inhibition of SCoV2-PLpro with GRL-0617 impairs the virus-induced cytopathogenic effect, maintains the antiviral interferon pathway and reduces viral replication in infected cells. These results highlight a potential dual therapeutic strategy in which targeting of SCoV2-PLpro can suppress SARS-CoV-2 infection and promote antiviral immunity.
【초록키워드】 SARS-CoV-2, coronavirus, Antiviral, SARS-CoV, SARS-COV-2 infection, Infection, interferon, severe acute respiratory syndrome Coronavirus, viral spread, type I interferon, Papain-like protease, Protein, specificity, Viral, viral replication, immune responses, cleavage, IRF3, target, cytopathogenic effect, respiratory, crystal structure, PLPro, antiviral immunity, interactions, mechanism, therapeutic strategy, NF-κB, host proteins, Interaction, ISG15, interferon pathway, dual, antiviral immune response, post-translational modification, acute respiratory syndrome, Regulation, biochemical, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, enzyme, infected cells, complex, domain, host protein, high affinity, interferon-stimulated gene, ubiquitin, polyprotein, sequence identity, Host, responses, highlight, NF-κB pathways, required, generate, functional, contribute, promote, maintain, reduce, suppress, reveal, implicated, impair, highlighting, attenuate, cleave, cleaving, 【제목키워드】 Innate immunity, protease, Spread, Viral, regulate, SARS-CoV-2 viral,